Combustion initiator



Sept. 17, 1957 T. R. R. BOCCHIO 2,806,356

COMBUSTION INITIATOR Filed Aug. 27, 1952 FIG. I.

THEODORE RAYMOND 1?. 8000/00 1 BY I I ATTORNEYS INVENTOR but which is 2,8fi6,356 Patented Sept. 17, 1957 COMBUSTIQN INITIATOR Theodore Raymond R. Bocchio, Lemon Grove, Califl, assignor to the United States of America as represented by the Secretary of the Navy Application August 27, 1952, Serial No. 306,626 3 Claims. (Cl. 60-39.82)

This invention pertains, in general, to aerial missiles of the ramjet type, and more specifically to a combustion initiator for assisting in the combustion process in ramjet missiles.

In the past, considerable difficulty has been encountered in initiating and sustaining the combustion process of the air-fuel mixture in namjet missiles. This difliculty is due to several different factors, such as the high velocity and turbulence of the air medium passing through the ramjet missile, and pulsations and vibrations caused by the burning of the combustion mixture.

It is one of the objects of this invention, therefore, to provide a combustion initiator arrangement which will assist materially in starting the combustion process in a ramjet missile.

It is another object of this invention to provide a combustion initiator arrangement which is simple in construction, and reliable and cflicient in operation for carrying out the initial step of starting combustion in the aerial missile.

It is another object of the invention to provide a combustion initiator arrangement in which the air and fuel mixture enter the combustion chamber in a swirling motion at approximately stagnation pressure such that the air and fuel mixtures are uniformly mixed and are effectively ignited by a flare member.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, and in which:

Fig. 1 is an axial section showing the combustion initiator arrangement in side elevation;

Fig. 2 is an axial section of the combustion initiator arnangement taken on line 22 of Fig. 3; and

Fig. 3 is a front elevation of the combustion initiator arrangement shown in Fig. 2.

According to the invention, a combustion initiator arrangement is provided for aerial missiles of the ramjet type in order to initiate or start the combustion process therein. This arrangement comprises a frusto-conical can which is open upstream from the combustion chamber substantially closed downstream, in order that the pressure in the can member will be substantially equal to that of stagnation pressure. The downstream portion of the can member has a plurality of outlet apertures therein. A flare and a baffle are provided at the open end of the can member, whereby the air and fuel mixture will enter therein in a swirling motion at about stagnat on pressure. The flare will ignite the air-fuel mixture and the burning products therefrom are allowed to escape into the main air-fuel stream through the apertures in the downstream end of the can member. These burning products are utilized to ignite the main air-fuel mixture in the main combustion stream.

Reference is now made to the figures of the drawing, for a more complete understanding of the invention. In Fig. 1, there is partially shown an aerial missile of the ramjet type having a forward or diffuser section 12 and a combustor section 14. Between the diffuser section 12 and the combustor section 14 there is mounted, by means of gutter members 16, the combustion initiator arrangement 18 comprising the present invention.

This combustion initiator arrangement comprises a frusto-conical member or can 20 which has its larger and open end 22 upstream and which has its smaller and substantially closed end 24 downstream. A plurality of apertures or openings 26 are provided in the smaller end 24 in order that the products of combustion from the air-fuel mixture may escape therethrough into the main air-fuel stream 28 flowing outside of and around the combustion initiator arrangement 18. i

The forward end 22 of the initiator arrangement has a plurality of transverse stationary blades 30 mounted therein. Each blade is twisted along its radial direction and thus-each blade is arranged at a substantial angle to the direction of air-fuel flow as best shown in Fig. 3. The outermost ends 32 of the blades are welded or attached in some suitable manner to the can member 20. while the inner ends 34 are used to support a holder 35 for a flare 36. The inner ends 34 can be attached to the flare by welding or by any other suitable arrangement.

The gutter members 16 are likewise attached to initiator arrangement 20 by means of welding or the like and can be rigidly mounted between diffuser section 12 and combustor section 3.4 or it may be supported as shown in Fig. 1. In Fig. 1 there is shown an annular ring 38 located between diffuser section 12 and combustor section 14. The ends 49 of gutter members 16 are inserted in slots (not shown) provided in annular ring 38. Two additional annular rings 42 and 44 cooperate with annular ring 38 by means of the cutout shoulders 46 and 48 provided on these rings. Rings 42 and 44 have provided in them a plurality of openings 50 for receiving bolts 52 which are passed first through ring 42 and then through ring 44 and the threaded ends 53 of bolts 52 are received in the threaded openings 54 in a fourth annular ring 56. A rubber annular ring 58 may be provided between annular rings 44 and 56 as shown in Fig. 1 in order to assist in the mounting of a fuel tank 50 between the walls 62 of the diffuser 12 and the outer wall 64 of the aerial missile 10.

Having described the structural arrangement of the combustion initiator arrangement, its operation will now be briefly explained. The aerial missile 10 after being launched by a booster rocket from a launching platform (both not shown) continues along its trajectory until the booster rocket has consumed its propellant. The booster rocket then separates from the ramjet missile 10 and drops earthwardly. The ramjet missile 10 meanwhile, due to the booster rocket, has gained sufiicient velocity to begin functioning by generating its own source of power. The air passing through the diffuser section 12 has injected into it near the end of diffuser section 12 a certain fuel. The air and fuel are mixed, and flow together downstream. A portion of the air-fuel mixture enters the open end 22 of the can member 26 and due to the blade members 30 the air-fuel mixture is further mixed. The flare 36 is ignited by remote control or by other electrical means connected to the flare by leads 37. The flare 36, in turn, ignites the air-fuel mixture flowing in can member 20. The burning products of combustion from the ignited airfuel mixture in can 20 are allowed to escape through the openings 26 therein. bustion are then utilized to ignite the main air-fuel mixture flowing around and outside of can'member 20.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that Within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

These burning products of com-' l. A combustion igniter arrangement'for an aerial missile of the ramjet type, having a diffuser, comprising, a frusto-conical member mounted in said diffuser and having 'its larger, iopened end upstream for receiving and shielding a portion of an air-fuel mixture from the main air-fuel stream flowingthrough said'missile at substantially'stagnation'pressure, said frusto-conical member having its smaller, closed'end downstream, the side wall of said frusto-conical member having a plurality of small openings thereinnear its downstream end, a hub, means for swirling andmixing said received air-fuel mixture, said 'swirling means being located at said opened upstream end of said 'frusto-conicalmember and including aiplurality of blades radiating outwardly from said hub and twisted along a'radial direction, the outer ends of said blades being attached to said frusto-conical member, means in said hub forigniting said air-fuel mixture in said "frusto-conical member, and'means attached to the downstream end of said frusto-conical member for mounting saidfrusto-conicalmember to said ramjet missile at substantially thedownstream end'of said diffuser whereby when said air-fuel mixturein said member is ignited by saidigniting means, the products of combustion liberated by the burningof said mixture escape through said openings in said frusto-conical member to ignite the main air-'fuel-stream flowing through said missile.

2. A combustion igniter arrangement for an aerial missileof the ramjet type having a diffuser and a combustor, comprising, a frusto-conical member mounted in said difluser andhaving its larger, opened end upstream for receiving and shielding a portion of an air-fuel mixture from the-main air-tuel'stream flowing through said missile atsubstantially stagnation pressure, said frusto-conical member having its smaller, closed end downstream, the sidewall-of said frusto-conical member having a plurality of small openings near its downstream end, a hub, means for swirling and mixing said received air-fuel mixture, said swirling'means-being located at the upstream end of said'frusto-conical member and including a plurality of blades radiating outwardly from said hub and twisted along a radial direction, the outer ends of said blades being attached to the upstream end of said irusto-conical member, flare means in said hub for igniting said airfuel-mixture in said frusto-conical member,a plurality of gutter-type members,'and a plurality of annular rings,

said gutter-type members radiating outwardly from said frusto-conical member and having their outer ends received in slots provided in one of said plurality of annular rings, said one annular ring for receiving said outer ends of said gutters being mounted between at least two other of said plurality of annular rings, all of said annular rings being located between said diffuser and combustor of said aerial missile whereby when said air-fuel mixture in said member is ignited by said flare means, the products of combustion liberated by the burning of said mixture escape through said openings in said frustoconical member to ignite the main air-fuel stream flowing through said missile.

3. A combustion initiator arrangement for an aerial missile of the ramjet type, comprising, a frusto-conical member having an open end upstream for receiving and shielding a portion of an air-fuel mixture from the main air-fuel stream flowing through said missile at substantially stagnation pressure and a closed end downstream, the side wall of said frusto-conical member having a plurality of small openings near its downstream end, a hub, means for swirling and mixing said received air-fuel mixture, saidswirling means being located at the upstream end of said frusto-conioal member and including a plurality of blades radiating outwardly from said hub and twisted along their radial direction, the outer ends of said blades beingattached to saidfrusto-conioal member, and means located in and shielded by said hub for igniting said airfuel mixture in said member, whereby a portion of said air-fuel mixture 'entering said frusto-conical member at substantially "stagnation pressure is ignited by said igniting means, with the products of combustion therefrom escaping through said openings in said downstream end of said frusto-conical member to ignite the main air-fuel stream flowing through said missile.

References Cited in the file of this patent UNITED STATES PATENTS 2,410,881 Hunter Nov. 12, 1946 2,520,388 Earl Aug. 29, 1950 2,618,928 Nathan Nov. 25, 1952 2,627,810 Catlin Feb. 10, 1953 2,632,299 Loughran Mar. 24, 1953 2,632,300 'Brzozowski Mar. 24, 1953 2,679,137 Probert May 25, 1954 

